Loss of blood and bodily fluids during surgery is presently accounted for by antiquated methods. Sponges of uniform size are used to absorb the blood and fluids and the sponges are laid out on a fabric or plastic sheet or otherwise arranged where they can be easily inspected and counted. This task typically falls on the anesthesiologist who visually estimates the quantity of blood and fluids contained in the sponges.
Estimating loss of blood and fluids by examining sponges is an art. Conventional wisdom holds, for instance, that surgeons tend to underestimate blood loss while anesthesiologists overestimate it. Further, fluid may evaporate as sponges lie waiting to be counted and thus cause estimations to vary. Surrounding material, such as fabric on which the sponges are placed, can also absorb fluid and affect the estimate.
Blood and other body fluids have also recently begun to be thought of as biocontaminants which require careful handling, management and control. Earlier techniques such as laying sponges out on sheets to account for blood loss are thus more frequently thought of as unacceptable. The need arises for a way to account for body fluids from the patient while at the same time ensuring minimum risk of contamination from such fluids.